Fluid-pressure tank



Sept. 11, 192&

w. A. COATES FLUID PRESSURE TANK Filed June 4, 1925 I INVENTOR Wilham A. Coares WITNESSVES: V

ATTORNEY Patented Sept. 11, 1928.

UNITED STATES 1 m NT: on ICE .1

WILLIAM a mans, F crroRLTomoUM-HARn/Y, ENGLAND, Assrenon T0 WESTING- nousn ELECTRIC & MANUFACTURING coMrANY, A CORPORATION OF PENNSYL- VANIA.

FLUID-PRESSURE TANK.

Applica-titmgflled June 4; 19 28, Serial No 643,223, and in Great Britain June 23, 19 22. Q

My invention relates to fluid-immersed electrical ClBVlCQS, and more particularly to means for ventilating the containers for the same.

Oneobject of my" invention is to provide improved means for venting the space above the fluid in fluid insulated electrical devices;

In accordance with the invention the upper 'part of thetank of an oil-immersed eleciti'ical' device, such as. a'switch, circuit-interruptersor a transformer, is provided with at least'two vents which open to the atmos phere at different levels, the lower vent beingnormal-ly open and provided with a nonreturnvalve which is adapted to close the vent when the pressure within the tank exceeds a predetermined amount and the upper vent being permanently open.

In order that the invention may be more clearly understood and readily carried into practice reference will now be made to the" accompanying drawing, which represents by way of example a fragmentary vertical section through the tank of a fiuiddmmersedcin wit-interrupter equipped in accordance with the invention. The fluid generally employedis oil of high grade.

In the form illustrated, the tankcover 1 is provided with vent openings 2 and 3, the former containing'a horizontal vent pipe 4 and the latter communicating with an elbow vent-pipe 5 adapted to discharge to atmosphere at a higher level than the vent pipe 4. The vent pipe 4 is provided at its inner end with a pivoted flap valve 6, and the pipe 5 is provided at its upper'end with a cap 7 having lateral discharge openings 8 therein and depending from the center of which is a sphere 9. A liquid receptacle 10, which communicates with theinterior of the pipe through drains 11, is formed between the cap 7 and the. exterior of the pipe 5. Inoperation, the vent pipe 4 is, owing to the inclination of its inner end and the disposition of the flap valve 6, normally open while the vent pipe 5 is permanently open. When an arc occurs, as upon the opening of the circuit interrupter or upon the occurrence of a short-circuit, a considerable amount of gas is liberated and the increased pressure within the tank causes the valve 6 to close the vent pipe 4, the gases then escaping only in the tank tea predetermined extent the weight otthe valve 6, which may in some cases be assisted by a spring 12, causes it to fall and open the vent 4 while there is still a streaniof gas issuing through the vent 5.

This current of gas draws in fresh" air throughthe lower vent by reason of the difference in level betweenthe two vents, this action continues for a suiiici'ent time to ensure that the whole of the upper part of the tank is exhausted of the products of combustion of the oil. V

It will be apparent that the sphere 9 and cap? serve as battles to prevent oil being projected completely through the vent 5 while the cap 7 serves also to prevent the ingress of moisture while the device is used in an exposed position. In the event of any small quantity of oil being projected through the orifice of the pipe 5 it will be collected in the receptacle 10 and will flow back to the tank through the drains 11.

The invention is not limited in regard to the'precise location of thevents and it will be obvious that. more than two of such vents may be provided if desired.

Although I have described a specific em bodiment of my invention, it will be obvious I tions and levels, one of said vents being open under all conditions of pressure insaid tank, and another of sald vents being adapted for closing under predetermined pressure conditions in said tank.

' 2. In an electrical device, the combination with a tank, an insulating fluid in said tank,

and an electrical device submerged'in said fluid, of venting means for said tank comprising a plurality of vents at different levels and positions, the vent at the higher level being openrunder allconditions of pressure in said tank, and anotherqof said vents being adapted for elosingunder predetermined pressure conditions in said tank.

3.111 an electrical device, the combination with" a'iank, an insulating fluid in said tank, and an electrical device submerged 'in said fluid, of venting means for said tank COITlprising a plurality of vents at different levels and positions, the vent at the higher level being open under all conditions of pressure in said tank, and a vent at a lower-level being adapted for closing under predetermined pressure conditions in said tank.

I 4. I Inan electrical device,.the combination with atank, an insulating fluid in said tank, and an'electricaldevice submerged in said fluid, of ventingineans for said tank comprising a plurality of vents at different levels and positions, one of said vents being adapted for the release off-gases under all conditions of pressure withinsaid tank, and another of said vents being adapted for selectively controlling the admission of air. to said tank.

5. In an electrical device, a tank,an vinsulating fluid in said tank, and an electrical .adapted for closing under predetermine pressure conditions in said tank whereby a stream of air is normally 'eaused to move across the surface of the insulating fluid.

6 The combination with a vertical" vent pipe of aeap covering the end of said pipe,

perforations opening laterally from the Wall of said pipe adjacent said cap, an annular trough on the interior of said cap below Said I openings, and means for draining said trough into said pipe. y l

7. The combination with a verticalvent pipe having a reduced diameter at the end thereof, of a capfitting over the end of said pipe, perforations opening laterally from the wall of said pipe adjacent the end thereof, an annular. trough below said openings, means for draining said trough. into said pipe, and w a member suspended from said cap and adapted to obstruct the opening of said pipe.

In testimony whereof, I have hereunto subscribed inyname this 9th day of May, 1923. \VILLIAM A. COATES. 

